There is a increasing need for data on effectiveness of care for patients with major psychiatric disorders, that is, for data on the outcomes achieved in actual practice settings. We propose to use data from a large quasi-experimental study, the Medical Outcomes Study, to examine how outcomes of care and the clinical appropriateness of care for depressed patients varies according to characteristics of the health care delivery system in which the patient receives care, particularly by type of provider treating the patient (general medical clinician or mental health specialist), type of payment for services (prepaid or fee-for-service) or other practice characteristics such as group size. We will estimate the association between type of payment and other practice characteristics and two types of outcomes: level of functional status; and satisfaction with care. We will rely on standardized measures which assess multiple domains of each of these two types of outcomes. We will estimate associations between practice characteristics and several components of the process of care: level of use of general and mental health services; detection of depression by the treating provider; clinical appropriateness of the psychotropic drugs used by depressed patients; and continuity of care. We will explore explanations for associations between practice type and outcomes by thorough examining associations among practice type, treatment style, patient outcomes, and patient and clinician psychological variables (attitudes; treatment adherence) and external factors (social supports, life events). We will formulate and test alternative overall models of predictors of outcomes using structural modeling and instrumental variable analyses. The analytic strategy relies on multiple regression models which control for initial severity of illness and careful accounting for design effects. The proposed investigators represent multiple health service research disciplines, and have extensive experience with the MOS data base.